i saw this idea in a magazine a few years back and it has been stuck in my memory and this year we finally got around to making it.
a shallow pot about 12" in diameter
one small pot
wheat grass seeds (soak the seeks for 24 hours before adding them to the dirt)
a rock large enough to cover the opening of the smaller pot.
we first read one of the kid's Easter books. we talked about where they took Jesus after he died on the cross.